1. Technical Field
The present disclosure generally relates to digital media devices, and more specifically, to time-shift buffering in a digital media device.
2. Description of the Related Art
Digital media recording devices can be used for recording media signals, such as audio and/or video signals, in a digital format. Such devices may also be used for the storage and playback of such signals. One specific example of such a digital media recording device may be referred to as Digital Video Recorder (DVR) or Personal Video Recorder (PVR).
In general, a DVR may be used to schedule and record future television programs, for buffering live television programs in a time-shift buffer, and/or playback of the digitally recorded television programs. The incoming media signals representing the television programs may be received, potentially decrypted and/or encoded, and digitally stored on a storage medium. The storage medium is commonly a non-volatile storage device such as a hard disk drive (HDD) (i.e., hard drive), among other acceptable mediums. Such an HDD can write the digital media data on a magnetic surface of the HDD disk platters and read the media data at later times for playback.
A conventional DVR may first record incoming media content to a time-shift buffer, and if desired, this media content may then be stored to a more permanent linear recording. However, using conventional designs, recording media content to the time-shift buffer before storing the media content to the more permanent linear recording can introduce problems affecting the user experience. For example, in the case of consecutively recorded (i.e., back-to-back) linear recordings, the second of the recordings may lose a portion of the beginning of the desired content. Specifically, according to conventional DVR designs, the time-shift buffer is stopped and restarted (i.e. which can include flushing the recorded media content out of the buffer) in between scheduled recordings. One potential effect of this is that, if a second tuner (which may have its own associated time-shift buffer) is not available to service the second of the back-to-back recordings, the second recording is delayed until the first recording finishes a conversion from the time-shift buffer to a permanent linear recording. Once the first of the back-to-back recordings finishes its conversion, the second recording may begin directing media content to the restarted time-shift buffer resource, which could be several seconds or minutes later (thus a portion of the beginning of the second requested media content is lost).
Additionally, regardless of whether linear recordings are first stored to a time-shift buffer, conventional DVRs are configured to reset the time-shift buffers when service contexts are attached and/or detached. Such service contexts are, for example, the main output for display and/or a PIP display. Accordingly, actions such as channel changes or picture-in-picture (PIP) swaps may cause media content previously recorded to a particular time-shift buffer associated with the service context to be discarded. Thus, if a user channel surfs from a first channel to a second channel, the buffer associated with the first channel is reset and the second channel begins using a fresh time-shift buffer. Thus, as a consequence, the user cannot rewind through media content previously recorded to the time-shift buffer while viewing the first channel. This is true even if the user switches back to the first channel. Similarly, if a PIP display includes a first channel as the main display and a second channel as the PIP, any content previously saved to a time-shift buffer associated within the main or PIP displays may be discarded and no longer accessible after swapping between the main and PIP display.
Accordingly, it is desirable to provide a media recording device that can be configured to mitigate these potential deficiencies, among others.